Light-emitting devices

Abstract

A light-emitting device comprises a semiconductor layer sequence comprising a first semiconductor layer having a first electrical conductivity, a second semiconductor layer having a second electrical conductivity, and an active layer interposed between the first semiconductor layer and the second semiconductor layer; a plurality of beveled trenches formed in the semiconductor layer sequence; a plurality of protruding structures respectively formed in the plurality of beveled trenches; a dielectric layer formed on the second semiconductor layer and an inner sidewall of the plurality of beveled trenches; a reflecting layer interposed between the semiconductor layer sequence and the dielectric layer; and a metal layer formed along the inner sidewall of the plurality of beveled trenches, wherein the dielectric layer, the reflecting layer and the metal layer are overlapping, the plurality of protruding structures and the reflecting layer are not overlapping.

What is claimed is: 
     
       1. A light-emitting device, comprising:
 a semiconductor layer sequence comprising a first semiconductor layer, a second semiconductor layer, and an active layer interposed between the first semiconductor layer and the second semiconductor layer; 
 a beveled trench formed in the semiconductor layer sequence, comprising a top end, a bottom end exposing the first semiconductor layer and an inner sidewall connecting the top end and the bottom end; 
 a protruding structure comprising metal formed at a position corresponding to that of the beveled trench; 
 a dielectric layer formed on the second semiconductor layer and on the inner sidewall of the beveled trench; 
 a reflecting layer comprising one portion contacting a main side of the second semiconductor layer, and another portion extended outside a sidewall of semiconductor layer sequence, wherein the another portion comprises a surface coplanar with the main side of the second semiconductor layer; 
 an electrode formed on the surface of the another portion of the reflecting layer, wherein the electrode is separated from the sidewall of semiconductor layer sequence by a distance; and 
 a metal layer formed along the inner sidewall of the beveled trench to extend outside the beveled trench. 
 
     
     
       2. The light-emitting device according to  claim 1 , wherein the protruding structure is surrounded by the reflecting layer. 
     
     
       3. The light-emitting device according to  claim 2 , wherein the metal layer and the protruding structure are overlapping. 
     
     
       4. The light-emitting device according to  claim 1 , further comprising a plurality of beveled trenches and a plurality of protruding structures respectively formed in the plurality of beveled trenches, wherein the plurality of protruding structures are separated from each other in a cross-sectional view of the light-emitting device, and the metal layer comprises a circular shape in a top view of the light-emitting device. 
     
     
       5. The light-emitting device according to  claim 4 , further comprising a first electrode formed on the plurality of protruding structures. 
     
     
       6. The light-emitting device according to  claim 1 , wherein the dielectric layer comprises a surface perpendicular to a thickness direction of the semiconductor layer sequence, and the metal layer extends onto the surface of the dielectric layer. 
     
     
       7. The light-emitting device according to  claim 1 , wherein the protruding structure does not form on the second semiconductor layer. 
     
     
       8. The light-emitting device according to  claim 1 , wherein the protruding structure and the beveled trench comprise a similar shape from a top view of the light-emitting device. 
     
     
       9. The light-emitting device according to  claim 1 , wherein a circumference of the protruding structure is smaller than a circumference of the beveled trench. 
     
     
       10. The light-emitting device according to  claim 1 , wherein the protruding structure protruding outside the top end of the beveled trench in the thickness direction of the semiconductor layer sequence. 
     
     
       11. The light-emitting device according to  claim 1 , wherein the top end comprises an area larger than an area of the bottom end. 
     
     
       12. The light-emitting device according to  claim 1 , wherein the electrode, the reflecting layer, the dielectric layer and the metal layer are overlapping in the thickness direction of the semiconductor layer sequence. 
     
     
       13. The light-emitting device according to  claim 1 , further comprising a carrier substrate and a connection layer formed between the carrier substrate and the semiconductor layer sequence, wherein the connection layer comprises metal. 
     
     
       14. The light-emitting device according to  claim 13 , wherein the carrier substrate is conductive. 
     
     
       15. The light-emitting device according to  claim 13 , wherein the connection layer is formed between the metal layer and the carrier substrate. 
     
     
       16. The light-emitting device according to  claim 1 , wherein the active layer comprises InGaN-based material, AlGaAs-based material, or AlInGaP-based material. 
     
     
       17. The light-emitting device according to  claim 1 , wherein the reflecting layer comprises metal or metal alloy material. 
     
     
       18. The light-emitting device according to  claim 1 , further comprising a void formed at a position under and corresponding to a position of the beveled trench. 
     
     
       19. The light-emitting device according to  claim 1 , wherein the protruding structure and the reflecting layer are not overlapping. 
     
     
       20. The light-emitting device according to  claim 1 , further comprising a void formed under the metal layer.